Thorunna florens-Color variation

Dear Rebecca,
I have posted, at the top of this page, photos of the three colour "forms" of Thorunna florens including the one from Thailand you were inquiring about.

The Hong Kong colour form matches the "typical" Japanese specimens well, differing only to the extent that the purple submarginal line is broken up into a string of blotches in most reported Japanese specimens. At this stage I feel the Western Australian specimens have a colour pattern which can easily be derived from the Japanese pattern. In internal anatomy, including radular morphology, the Hong Kong and Western Australian specimens matched the Japanese material.

Concerning the Thailand specimen which you say has a differently shaped first lateral tooth. Until your message I had assumed that it was T. florens because the colour pattern was very similar to Japanese material, apart from the yellow lines being replaced by broader orange bands. One feature of T. florens appears to be the broad orange or yellow band around the anterior end of the mantle. This is present in the Thai specimen although it is difficult to see because the front of the mantle is damaged.

From memory, only two other species of Thorunna have broad orange red anterior mantle bands. By coincidence both are already illustrated in the Forum: Thorunna montrouzieri and Thorunna speciosus . Another species which looks something like the Thai specimen is Thorunna australis which I have just posted a picture of.

This doesn't solve the problem of the aberrant-toothed Thai specimen. I'm afraid I had only one specimen so there is little we can do but wait until more material turns up. Perhaps it represents a consistently distinct species, or perhaps it has an aberrant radula.

Concerning the Bali photo and the radula photo. I would very much like to see them and to include them in the Forum.

Best wishes
Bill Rudman.